Batman: Mask of the Phantasm - The Audio Drama (PAID)
Dave Holiday for Sal Valestra
Valestra plays a larger role in the film, but in my adaptation he only has one scene where he's trying to recruit The Joker to protect him. He is (understandably) extremely nervous all the while, so keep that in mind for your audition. Otherwise, I think that his voice in the film is great, so that could be a good starting point.
Voice example: https://youtu.be/MVy9DFwT-4o
(Unnerved, extremely nervous)
"I take it you know why I'm here. (Pause) Well in case you, uh, didn't hear, a couple of the boys from the old crew are, well... dead."
(Nervous yet desperate)
"Look... I don't know who it could be, but... Do you think you can help me out here? They'll be coming for you next anyways."
(Trying to save face)
"Oh, it was never personal! You were just... The best at all that, that's all."